Designing a TIR High Beam

This application note presents a complete workflow for designing a Total Internal Reflection (TIR) high‑beam optic using LucidShape in combination with external CAD tools, illustrating each stage from geometric construction to photorealistic rendering. The document guides optical engineers through creating a functional high‑beam module that meets performance and regulatory requirements, while demonstrating how LucidShape’s advanced design features and visualization capabilities streamline the process. The example begins by establishing the core model architecture and concludes with detailed instructions for rendering and tone‑mapping the final illumination result.

The workflow starts with constructing an axis pattern consisting of three individual axis systems that serve as the foundation for positioning all optical elements. This pattern is essential because each subsequent component — such as LEDs, collimators, and MacroFocal lenses — is aligned to these axes to maintain spatial and optical coherence throughout the model. After the axis pattern is created, LED light sources and collimators are placed simultaneously along the axis systems. The collimators are responsible for parallelizing the divergent output from the LEDs, ensuring the beam can be efficiently directed and shaped in downstream optical elements. Because the collimators must fit within the predefined housing, their geometries are transferred to an external CAD environment, trimmed accordingly, and then re‑imported into LucidShape.

In the next stage, the designer creates MacroFocal lenses, an advanced LucidShape design feature used to control and refine the light distribution within the TIR optic. These lenses are positioned on the same axis pattern to ensure accurate alignment. Afterward, the previously trimmed collimators are intersected again in CAD with the newly created MacroFocal lenses to form the complete TIR body. When the geometry returns to LucidShape, optical properties are assigned to the trimmed surfaces, enabling them to properly participate in simulation and ray tracing. This step ensures the accuracy and realism of the final illumination pattern.

Once geometry preparation is complete, the design enters the ray‑tracing and performance‑evaluation phase. Here, the engineer iteratively adjusts the lens spread angles to tune the output pattern. A test table is then used to evaluate whether the resulting high‑beam meets legal photometric requirements. This stage demonstrates how engineers can refine the illumination distribution through controlled parameter adjustments while relying on LucidShape’s built‑in evaluation tools.

To visualize the system in a real‑world context, the workflow concludes with the creation of a photorealistic rendering of the completed high‑beam module. LucidShape’s Luminance Camera in backward ray‑trace mode is used to generate a realistic image of the headlamp within its environment. An environment light source is added to represent the surroundings. Because the environment source introduces high luminance values, the rendering requires Human Eye Vision Image (HEVI) post‑processing, ensuring realism through accurate tone mapping. Additionally, a Vos glare model is applied to emphasize the glow around the high‑beam emitters, increasing authenticity and visual fidelity. This final step demonstrates LucidShape’s capability to combine physical simulation with visualization techniques to produce final images suitable for design reviews or customer presentations.

The application note concludes by summarizing what the engineer gains from this example: experience creating a TIR high‑beam optic, integrating it into an existing housing, transferring geometries between LucidShape and CAD tools, assigning optical materials, and using MacroFocal lenses to achieve a light pattern that satisfies regulatory high‑beam requirements. It also reinforces the role of the Luminance Camera and HEVI in generating high‑quality, human‑perception‑aligned visual output.

A set of example files supports the entire workflow, including step‑by‑step models for each stage (axis setup, collimator trimming, MacroFocal insertion, and final TIR body), as well as a spectral distribution file and an example of traced results that can be used for tone‑mapping exercises. These resources help streamline adoption for engineers learning or refining their LucidShape workflow.

Overall, this document serves as a practical, end‑to‑end guide for engineering teams developing high‑beam optics using TIR principles. It demonstrates how LucidShape’s parametric design tools, CAD‑integration workflow, optical property assignment, and advanced rendering capabilities can be combined to efficiently produce high‑quality, regulation‑compliant automotive lighting systems.